Automotive refrigeration systems of the type having a thermostatic expansion valve may benefit from having a receiver fitted into the system between its condenser and such valve to provide for storage of a volume of refrigerant sufficient to accommodate for variations in system operating conditions and loss of refrigerant due to diffusion and small leaks.
For a receiver to be effective, it must be arranged downstream of the point at which condensation of the refrigerant occurs, have an internal configuration including sufficient volume and/or internal centrifuge or baffling to permit separation of the gaseous and liquid phases of the refrigerant, have a liquid outlet arranged to communicate with liquid below the gas/liquid interface, and the refrigeration system be charged with a quantity of refrigerant such that the gas/liquid interface occurs within the volume enclosed by such receiver under applicable operating conditions.
Where an automotive refrigeration system is provided with a receiver and the refrigerant charge level of the system does not overfill the receiver under applicable operating conditions, a conventional condenser provides essentially zero refrigerant subcooling. In the event that overfilling of the receiver occurs, a conventional condenser may provide a level of subcooling that varies directly with the amount of refrigerant overfill and system operating conditions, but it is desirable to substantially avoid such subcooling in that it decreases the volume within the condenser available for condensing of refrigerant resulting in higher condenser pressures and lower system performance.
Automotive refrigeration systems operating with a receiver and a proper refrigerant charge level such as to maintain the gas/liquid interface within the volume enclosed by such receiver under applicable operating conditions may achieve higher performance levels with given system components by employing a separate subcooler arranged between the receiver and the thermostatic expansion valve. However, known systems employing subcoolers have the disadvantages of added cost, complexity, and a greater possibility of refrigerant leaks.